The invention relates to a solid fuel distributor and, more particularly, to a frame seal for a solid fuel distributor.
In certain furnaces that burn solid fuel, such as coal, a distributor projects the solid fuel into the furnace. Typically, a distributor comprises a rotating wheel (rotor) having blades extending radially outward therefrom. These blades are usually mounted in rows generally parallel to the axis of the rotor, and as the rotor rotates, the blades project the solid fuel into the furnace. Such distributors may be known as “underthrow” or “overthrow” distributors, depending on the direction of rotation of the rotor. For example, in an underthrow distributor, the rotor rotates such that the blades move the solid fuel under the rotor's axis and into the furnace. In an overthrow distributor, the rotor rotates such that the blades move the solid fuel above the rotor's axis and into the furnace.
The projection of solid fuel from one or more distributors results in a substantially uniform distribution of coal onto a stationary or moving grate (stoker) within the furnace. The stoker surface may be stationary or moving, and some or all of the air for combustion travels through the stoker. Within the furnace, fines are burned in suspension while larger particles fall and burn on the stoker.
Typically, solid fuel is provided to the distributor from by a feeder, which may include a conveyor assembly that conveys substantially uniform increments of the solid fuel from a coal silo to the distributor. The conveyor assembly drops the coal to fall in between respective pairs of the rotating blades of the distributor, and the distributor further conveys the coal to the furnace. The feeder and distributor may share a common housing, with the assembly being referred to as a feeder assembly.
While some components and sub-assemblies on the feeder assembly can be serviced with the furnace online, if the distributor is removed, the operator will be directly exposed to the combustion inside the furnace. Therefore, to perform maintenance on the distributor, the furnace must be taken offline, thus causing a loss in steam generation of the plant. Thus, there remains a need for a frame seal for performing maintenance on the distributor of the feeder assembly.